Answers

Best Answer: I'm not sure what you mean by volume. Do you mean loudness or the file size?

Anyway, don't obsess too much about audio file format. MP3 is by far the most common. If you want better quality, then use higher bitrate. At 320 mbps and higher, I think you'll be imagining things if you detect deficiencies relative to the original material. I think you'll also do better with VBR (variable bit rate) encoding, which does a more efficient allocation of encoding bits depending on the local activity entropy or business) of a song.

In the end, file compatibility may be more important than file format/encoder.

The type of file has no relation to volume..
Wav in it's original recorded form is the best format in the list apart from m4a which is the Apple lossless format.
Mp3, Ogg, aac and wma are all compressed (lossy) formats in which audio information is discarded to enable the smaller file sizes. There is an associated reduction in quality although this is not always readily heard unless played on a high quality stereo system.

The quality advantage of a wav file can be offset by it's size on disk.
A wav file of about 50 Mb can be reduced to abut 5 Mb if compressed to mp3 format.
A compression ratio of about 10:1.

Mp3 format is probably the most versatile format in that it can be played by any audio player and be used in most if not all audio editing programs.
It's main disadvantage being it is not recognized by older CD players if burned to disk.
Only tracks burned in wav format are recognized and played by all CD players, new or old.
A compression ratio of 320 kbps is the highest quality mp3 file.
128 kbps is generally acknowledged as the best compromise between file size and quality.